Acriflavine for Aquarium Fish

angelfish in an aquarium
V.v/Flickr/CC BY-ND 2.0 
  • Name: Acriflavine
  • Other Names: Euflavine, gonacrine, neutroflavine, and trypaflavine
  • Action: Antiseptic, dye, and protozoacide.

History & Uses 

Initially developed in 1912, acriflavine was obtained from coal tar and is available as an orange-brown powder. It was first introduced as an antiseptic and was used during WW1 to combat the parasites that caused sleeping sickness. At one time it was used in the treatment of gonorrhea but has since been replaced by more effective antibiotics. Acriflavine is now used primarily as a topical antiseptic and is often mixed with proflavine for commercial preparations.

In the aquarium hobby, it is used to treat a variety of ailments from bacterial and fungal infections in fish to disinfecting and treating open wounds. Acriflavine is also used to disinfect fish eggs, thus preventing egg loss to fungus. It may also be used as an alternative to Malachite Green for the treatment of disease in scale-less fish such as catfish, elephant-nose, and some members of the Characin family.

Diseases Acriflavine Is Used for, Either Prevention or Treatment:

  • Oödinium pilularis - Also known as Velvet Disease, this is actually caused by a protozoan parasite.
  • Flavobacterium columnare - this bacteria causes a disease known as Columnaris or Cottonmouth.
  • Fin Rot - Fins and tail become ragged and frayed, in some cases almost completely eroding, caused by several species of bacteria.
  • Egg Fungus - works as a mild disinfectant for fish eggs.
  • Saprolegnia - A fungal infection of freshwater fish.
  • Open Body Sores - Bacterial infection causing open red sores on the body.

Acriflavine can be used as a short term dip for the fish, or it can be added to the aquarium water to treat the entire tank. However, caution should be used in treating an entire tank, as it will stain artificial plants and decorations in the tank. To avoid staining, remove those items before treatment. Acriflavine will severely damage live plants and is therefore not recommended for use in live planted tanks. Instead, treatment should be carried out in a separate hospital tank, or if that is not possible, the live plants should be removed before treatment is begun.

Carbon in the filter will remove acriflavine from the water, and must be discontinued when acriflavine is used. An acid pH (below 7.0) will inhibit the efficacy of acriflavine. Wait for at least thirty minutes after using API Stress Coat, Kordon Novaqua, Kordon Amquel, Jungle Start Right, SeaChem Prime, and other Redox Reducing water products before using acriflavine in the aquarium.

Ammonia neutralizing or phosphate absorbing products, as well as Methylene Blue and antibiotics, will not impact the efficacy of acriflavine and can be safely used together with Acriflavine.

Do not use acriflavine with shrimp, crabs, or other crustaceans.

Products Containing Acriflavine:

FishVet Acriflavine-MS 

Acriflavine-MS is an effective preventative and treatment for the control of Oodinium (Velvet) in marine and freshwater aquariums, as well as for various external protozoan and bacterial infections. Acriflavine-MS is also used to prevent bacterial egg infections and to treat open wounds. To use as a bath (for preventing bacterial infections of fish eggs): Add 1 teaspoon per 5 gallons of water. After the eggs hatch, remove Acriflavine-MS by use of carbon and/or water changes. Use one dose only.

Manufacturer's Directions for Use: Add 1 teaspoon per 10 gallons of aquarium water. Treat daily after 25% to 50% water change. Adjust dose to match the amount of changed water.

API Fungus Cure Powder 

API Fungus Cure powder effectively treats fungus (Saprolegnia spp. & Achlya spp.), mouth fungus (Cotton Mouth Disease), and Fin & Tail Rot infections. Helps prevent the growth of fungus on fish eggs prior to hatching. For use in freshwater aquariums. Note: This medication will cause a slight discoloration of water which can be removed with activated carbon.

Manufacturer's Directions for Use: For best results, remove activated carbon or filter cartridge from filter and continue aeration. For each 10 gallons of water empty one packet into the aquarium. Repeat dose after 48 hours. Wait another 48 hours, then change 25% of the aquarium water and add fresh activated carbon or replace filter cartridge. 10 count powder packets of Fungus Cure treat up to 100 gallons. Two doses required for full course of treatment. Also available in a liquid form in 1.25 and 4-ounce bottles.

Tetra Parasite Guard 

Ingredients: praziquantel, diflubenzuron, metronidazole, acriflavine
Directions:Add one tablet to each ten gallons of aquarium water.
Remove carbon from filter during use. Treatment may be repeated up to two times with 48 hours between treatments and a 25% water change. For anchor worms and lice, repeat treatment up to three times using it once a week with a 25% water change.